Induced radioactivity of argon and krypton as active gas in atlas inner detector transition radiation tracker

In this study, estimates of the radioactivity levels of the Atlas inner detector transition radiation tracker gas system with alternative gas options of Argon and Krypton activated by neutron fluxes during the large hadron collider operations are presented. Considering the possibility of radioisotopes to be produced by the activation of gas, activities of these radioisotopes are calculated. Depending on the lifetime of the isotope produced, the resulting activity may be quite high. For maintenance issues, the workers need to be in the cavern and they would be exposed to the beta or gamma radiation produced by the radioisotopes of the Argon and Krypton gases. In addition, gas would be inhaled in the accessible areas and some radioisotopes result in an accumulative dose rate in the human body. Dose rates are also calculated for these radioisotopes to foresee the effect of radiation. Obtained results are compared with the original active gas which is Xenon. By the comparison, the ratio of activity and dose results of Argon and Krypton to Xenon is defined. Finally the results are discussed in view of CERN safety limits.